Gestational Age at Term and Teacher-Reported Attention-Deficit Hyperactivity Disorder Symptom Patterns

The objective of this study was to estimate associations between gestational age and teacher-reported attention-deficit hyperactivity disorder (ADHD)-related symptom patterns at age 9 years among children born at term (37-41 weeks).

A secondary data analysis of approximately 1400 children in the Fragile Families and Child Wellbeing study, a US birth cohort study that oversampled nonmarital births, was conducted. At age 9 years, students were evaluated by their teachers using the Conners Teacher Rating Scale-Revised Short Form that included subscales for symptoms of hyperactivity, ADHD, oppositional behavior, and cognitive problems/inattention. Unadjusted and adjusted negative binomial and logistic regression models of associations between gestational age and teacher-reported scores were estimated.

Each week of gestational age at term was associated with hyperactivity scores that were 6% lower (adjusted incidence rate ratio [IRR]: 0.94; 95% CI: 0.89-0.99) and ADHD and cognitive problems/inattention scores that were 5% lower (adjusted IRR: 0.95; 95% CI: 0.91-0.98 in both cases). Early-term birth (37-38 weeks) was associated with 23% higher hyperactivity scores (adjusted IRR: 1.23; 95% CI:1.07-1.41), 17% higher ADHD scores (adjusted IRR: 1.17; 95% CI: 1.05-1.30), and ∼50% higher odds of scoring 1.5+ SDs above the sample mean for hyperactivity (aOR: 1.51; 95% CI: 1.05-2.18) when compared with birth at 39-41 weeks. There were no significant associations between gestational age and oppositional behavior scores.

The findings add to growing evidence supporting current recommendations for delaying elective deliveries to at least 39 weeks and suggest that regular screenings for ADHD symptoms are important for children born at 37- to 38-weeks gestation.